SnO₂ Nanoparticles Decorated 2D Wavy Hierarchical Carbon Nanowalls with Enhanced Photoelectrochemical Performance

Abstract

Two-dimensional carbon nanowall (2D-CNW) structures were prepared by hot wire assisted plasma enhanced chemical vapor deposition (hw-PECVD) system on silicon substrates. Controlled variations in the film structure were observed with increase in applied rf power during deposition which has been established to increase the rate of dissociation of precursor gases. The structural changes resulted in the formation of wavy-like features on the 2D-CNW, thus further enhancing the surface area of the nanostructures. The FESEM results confirmed the morphology transformation and conclusively showed the evolution of the 2D-CNW novel structures while Raman results revealed increase in D / G ratio indicating increase in the presence of disordered domains due to the presence of open edges on the 2D-CNW structures. Subsequently, the best 2D-CNW based on the morphology and structural properties was functionalized with tin oxide (SnO 2 ) nanoparticles and used as a working electrode in a photoelectrochemical (PEC) measurement system. Intriguingly, the SnO 2 functionalized 2D-CNW showed enhancement in both Mott-Schottky profiles and LSV properties which suggested that these hierarchical networks showed promising potential application as effective charge-trapping medium in PEC systems.

Single-step growth of graphene and graphene-based nanostructures by plasma-enhanced chemical vapor deposition

“…For instance, electrochemically or catalytically active nanoparticles anchored onto VG-GNs could enable higher surface areas and benefit from the conductive VG-GN network. To date, nanoparticle inclusion into VG-GNs has only been achieved by post fabrication, and the methods used include sputtering [166], atomic layer deposition [102], solvothermal synthesis [167,168], spin coating [169] and electrodeposition [98,130]. Anchoring lithium titanate [102], hydrogen molybdenum bronze [98] and molybdenum disulfide [156,157] nanoparticles to VG-GNs have demonstrated enhanced performance of the resulting heterostructures in lithium and sodium ion batteries.…”

“…Anchoring lithium titanate [102], hydrogen molybdenum bronze [98] and molybdenum disulfide [156,157] nanoparticles to VG-GNs have demonstrated enhanced performance of the resulting heterostructures in lithium and sodium ion batteries. On the other hand, tin oxide anchoring to VG-GNs has shown improved formaldehyde detection [130] and photoelectrochemical performance [169]. In addition, silver, aluminum, cobalt, molybdenum, nickel, tantalum, and silicon nanoparticles have been explored for applications to surface-enhanced Raman spectroscopy [166].…”

Wettability of CNW/ITO Micro Structure for Modification of Surface Hydrophilicity

“…Figure 4b exhibits the Raman spectra of the pristine-CNW and CNW/ITO micro-structure. To the best of our knowledge, D (1350 cm −1 ), G (1580 cm −1 ), and 2D (2700 cm −1 ) are the common band of carbon materials, and a high D band and D band (shoulder band) is a unique band that can only be found in defected graphite [18][19][20]. In the Raman spectra of the CNW/ITO micro-structure from Figure 4b, it shows a low I D /I G ratio (1.71) with a low D band than pristine-CNW.…”